地基单站GNSS的电离层VTEC高精度解算方法

High Precision Algorithm for Ionospheric VTEC Based on Single Ground-based GNSS Station

利用IGS提供的双频GNSS观测数据,分析了 Kalman方法解算电离层垂直总电子含量(Vertical Total Electron Content,VTEC)存在的问题,提出了 Kriging-K alman改进解算方法,并对两种方法解算的电离层VTEC进行分析和比较.结果表明:在低纬地区,当观测卫星数量发生改变时,Kalman方法解算的VTEC存在跳变异常,Kriging-K alman方法解算的VTEC变化较为平稳,不存在跳变现象.对比分析耀斑期间两种方法解算VTEC的变化,发现Kalman方法解算的VTEC变化明显小于耀斑引起VTEC的增量;Kriging-K alman方法解算结果与实际变化相一致.表明Kriging-Kalman方法计算精度更高,能够更精确计算耀斑等剧烈异常空间天气活动期间的VTEC及其变化,有利于电离层VTEC日常精确监测、研究和工程应用.

Using the dual frequency GNSS observation data provided by IGS,the problems existing in Vertical Total Electron Content(VTEC)calculation using Kalman filtering method were analyzed,Kriging-Kalman algorithm was proposed,and the VTEC calculated by the two methods were compared.The results showed that:in the low latitude region,when the number of satellites in observation changed,the VTEC value calculated by Kalman filter method might have curve fracture anomaly;the VTEC value calculated by Kriging-Kalman method changed smoothly relatively.In addition,the changes of VTEC calculated by two method above during the flare were compared,it found that the change of VTEC calculated by Kalman filtering method was smaller than the increment of VTEC caused by flare,while the result of Kriging-Kalman method was more consistent with the actual change.All the results show that the accuracy of VTEC calculated using Kriging-Kalman method is higher in low latitude area,which can reflect the change of VTEC in abnormal space weather activities more accurately,and conducive to the daily accurate monitoring and engineering application of ionospheric VTEC.